Let me try to explaing this to you.
All browsers support the :hover pseudoclass on any object, except IE. IE only accepts it on the <a> tag. But, this file
is a sort of patch for IE that will make the :hover pseudoclass work on all elements. All you have to do is download it, and then link to it by adding this code in you <body> tag:
style="behavior:url(location of file relative to .html file);"
or in your stylesheet, like this:
style="behavior:url(location of file relative to .html file)";
Then any item can have a hover applied to it, and it will work in any browser.